1/2" gap rule? No gaps larger than 1/2"? Anti-snagging rule I suppose.
Looks like we're all in a rut as I Santa brought me Shewey's book as well. I've been using commerical burnt hackles but this is the first time I've read about how it's done. Nice to know.
There are a fair number of spey tiers in this neck of the woods, doing both fancies and traditionals. They fish the traditionals. I doubt I could bring myself to fish a fly that took so much effort to do right - especially with my liberal tendency of contributing to the RBBP.